[BUG] Padding issue in MultiTabs delegate example on iOS

[LeGoffMael]

Describe the bug
There is an unnecessary padding at the top of the grid view in the MultiTabAssetPickerBuilder example on iOS.

How to reproduce
Run the MultiTabAssetPickerBuilder example on an iPhone.

Expected behavior
The grid view and the path list dropdown widget should be stick to the top of the view.

It seems that it comes from kToolbarHeight at line 1197 and 1593 of DefaultAssetPickerBuilderDelegate.

Remove it fix the issue for MultiTabAssetPickerBuilder but the problem of padding appear on the commun pickers when shouldRevertGrid: false.

i could fixed it with an ugly fix, but it is definitely not ideal.

MediaQuery(
  data: MediaQuery.of(context).copyWith(
    padding: const EdgeInsets.only(top: -kToolbarHeight),
  ),
  child: Builder(
    builder: (BuildContext context) => Stack(
      children: <Widget>[
        RepaintBoundary(
          child: Column(
            children: <Widget>[
              Expanded(child: assetsGridBuilder(context)),
              if (isPreviewEnabled) bottomActionBar(context),
            ],
          ),
        ),
        pathEntityListBackdrop(context),
        pathEntityListWidget(context),
      ],
    ),
  ),
)

Screenshots (If contains)
the blue arrow shows the top padding

grid view	albums list

Version information

• Device: iPhone 11 pro
• OS: 16.1.1
• Package Version: master branch, 8.2.0
• Flutter Version: 3.3.9

[AlexV525]

This is likely caused by extra calculations when reverting the asset grid. I didn't pay too much caution when writing the multi-tab example.